The invention relates to a charging device comprised of a plug-in vehicle a charging electrical unit, a charging station and a charging cable to charge an energy storage unit of the vehicle through the wired charging connection, whereby the charging electrical unit includes a socket and the charging cable includes a plug to establish and disconnect the charging connection.
Hybrid or electric vehicles have an electrical powertrain with an electrical energy storage unit. The electric energy storage unit, which is usually designed as a high-voltage battery, is typically discharged during the driving operation of the electrical vehicle in motor operation and charged in generator operation. In addition, there is often an option to charge the battery by way of an external charging source. In conductive, i.e. cable-based charging, the vehicle is connected with a charging source through a charging cable. The charging connection is mainly established through a plug-socket contact, whereby the socket is comprised of the charging electrical unit of the vehicle. The plug forms part of the charging cable, which in turn is connected or can be connected with the charging station. The operation by the user of the vehicle is similar to the procedure at a gas station, i.e. to initiate the charging process the user applies the plug in the same manner as the user would put a fuel nozzle into the tank opening. Therefore, disadvantages restricting the comfort for the user are connected therewith. There is the risk of soiling one's clothing on the charging cable when operating the cable. In addition, the establishment and disconnection of the charging connection takes time. Because in the current state of the art, a plug-in vehicle must be far more frequently charged after it reaches its range than a vehicle with a combustion motor has to be refueled, the repetitive similar action of establishing a charge connection is associated with inconvenience and a loss of comfort, which is not acceptable or reasonable for a plug-in vehicle or user interested in a premium class vehicle. The same process applies analogous to the disconnection of the charging connection.
In the current state of the art, the response to these disadvantages is, for example, to provide docking systems to make the establishment and disconnection of a charging connection more comfortable for the user through automation. For this purpose, e.g. according to DE 10 2009 023 409 A1, the movement of the vehicle is used to establish a connection between a docking module mounted on the vehicle and a charging module on the charging station. The user perceives that the charging connection is established automatically during parking at a certain parking position. This has the disadvantage that it requires a complex construction of the charging station because of the necessary charging module. By utilizing the movement of the vehicle, the docking module can be placed only at the rear or front of the vehicle. Any potential mounting spaces on the sides of the vehicle, in the underside, or in the roof can hardly be considered. In addition, the vehicle must be steered with “utmost precision” to the charging module.
It is the purpose of the invention to provide an improved device to establish and to disconnect a charging connection automatically in a plug-in vehicle.
This objective is solved by providing a charging device according to the invention. The charging device, which for a plug-in-vehicle is comprised of a charging electrical unit and a charging cable to charge an energy storage unit of the vehicle through a cable-based charging connection, whereby the charging electrical unit has a socket and the charging cable has a plug, is characterized in that it has among others one or more insertion funnels at the socket. Furthermore, the plug has one or more insertion pins, whereby each insertion pin is allocated to a specific insertion funnel. In addition, if the charging connection is established, information can be exchanged between the charging station and the charging electrical unit and, if the connection is not established, information can be exchanged between the charging station and the vehicle. Furthermore, the plug and a reinforcement or stiffened section of the charging cable connected to the plug through a guiding mechanism, of which the charging station is comprised, moves in a predefined spatial direction in the form of a coupling movement through a maximum predefined coupling length and in the opposite direction of the predefined spatial direction in the form of a decoupling movement over the same coupling length.
The user has thereby the special advantage that the coupling movement and decoupling movement can replace using the plug manually.
According to a preferred embodiment of the invention, the guiding mechanism is designed as guide arm that can be operated by an electric motor. This guide arm guides the plug together with the reinforced section.
Alternatively, the guiding mechanism is designed as cable roll operated by an electric motor so that the plug with the reinforced section can be guided tangentially to the cable roll while the cable roll is rotating.
The guide arm or the cable roll achieves the technical effect that the plug is movable while executing the coupling movement or decoupling movement. This can be used to move the plug toward the vehicle or away from the vehicle.
In addition, it is advantageous if the information exchanged between the vehicle and the charging station to establish a charging connection includes information as to the position of the vehicle and the vehicle takes a charging position to establish the charging connection. This charging position is relative to the charging station within a predefined charging position range. Once the vehicle enters this charging position range and takes the charging position, this embodiment will indicate it to the driver and it initiates a coupling movement upon taking the charging position.
This means that a charging connection can be established if the vehicle is in the charging position.
In the charging position, the spatial distance between plug and socket is less than the coupling length. In addition, the charging position range that represents all charging positions available is defined by the opening surface of the insertion funnel or in several insertion funnels by the opening surface of the insertion funnel with the smallest opening surface.
In other words, the insertion funnel on the vehicle is within reach of the coupling movement of the plug once the charging position has been taken.
The charging position range is characterized in that once a charging position has been taken and the coupling movement has been realized, each of the pins penetrates the opening surface of the insertion funnel allocated to this pin and it enters the insertion funnel.
In addition, the reinforced section can be embodied as mechanical stiffening of the charging cable; this stiffening can be calculated so that the charging cable is, in the stiffened section, able to withstand any bending due to the earth's gravity of the plug and charging cable but bendable when the force, which exceeds the gravity of the plug and charging cable, is applied.
This specific form of the charging cable's flexibility in the reinforced section provides the option of a controlled deflection or curvature in this area of the charging cable.
According to a further embodiment, the socket may include several insertion funnels. The charging connection is established once the charging position is taken and every pin engages through the coupling movement in a respective insertion funnel allocated to that pin. If the coupling movement is carried out, every insertion funnel moves the entering pin in a guiding motion, which includes a spatial direction complementary to the spatial direction of the coupling movement and that bends the charging cable in the reinforced section. The coupling movement and the guiding motion move the plug into the socket and therefore make contact between plug and socket. Once the plug-socket contact has been established, the coupling movement stops.
In other words, the coupling movement in connection with the wall of the insertion funnel exerts a bending moment onto the cable in the reinforced section so that the plug is specifically guided into the socket.
Alternatively, the reinforced section can be stiffened to a mechanically rigid charging rod and the socket can be rigidly connected to each insertion funnel. In this case, the socket is controllable in two spatial directions, whereby these two spatial directions are complementary to the spatial directions, which describes the movement caused by the guiding mechanism of the charging station.
If the charging cable is reinforced so as to be a charging rod and the socket comprises several insertion funnels, then every pin engages through coupling movement in the insertion funnel allocated to that pin to establish the charging connection once the charging position is assumed. In the embodiment of the coupling movement, each pin that has entered the insertion funnel exerts a guiding motion onto the insertion funnel, which steers the controllable socket in the direction of the plug. The coupling movement and the guiding motion move the plug into the socket and therefore make contact between plug and socket. Once the plug-socket contact has been established, the coupling movement stops.
The special advantage of this embodiment is that the socket is controlled during the coupling movement from the guiding rod in a manner so that the plug is moved specifically into the direction of the plug.
Alternatively, the socket can have an insertion funnel that is designed rotationally symmetrical and positioned at neck of the funnel. Furthermore, the plug can have a pin and can be designed rotationally symmetrical. The plug can have a conical latch-like part, which works as pin.
The rotationally symmetric embodiment of the socket and plug ensures that only one funnel is sufficient to establish a dependable plug-socket connection.
In combination with the flexible charging cable in the reinforced section, to establish a charging connection, the plug latch enters into the funnel through coupling motion once the charging position is assumed. If the coupling movement is carried out, the insertion funnel moves the entering plug latch in a guiding motion, which includes a spatial direction complementary to the spatial direction of the coupling movement and that bends the charging cable in the reinforced section. The coupling movement and the guiding motion move the plug into the socket and therefore make contact between plug and socket. Once the plug-socket contact has been established, the coupling movement stops.
If a charging rod with a rotationally symmetrical plug, and a rotationally symmetric socket, are used, to establish the connection the plug latch enters the funnel through coupling motion once the charging position has been assumed. In the embodiment of the coupling movement, each plug latch that has entered the insertion funnel exerts a guiding motion onto the funnel, which steers the controllable socket in the direction of the plug. The coupling movement and the guiding motion move the plug into the socket and therefore make contact between plug and socket. Once the plug-socket contact has been established, the coupling movement stops.
Due to the rotational symmetry of the socket and plug, one insertion funnel and pin pair are sufficient to establish the intended contact. With regard to the joint rotational axis of the plug and socket, the plug and socket can assume any angular position. Since a non-rotationally symmetric socket and plug have to assume a specific angular position to establish contact, as described above, several insertion funnels and pins are used in this case so that the respective angular position is defined.
Once the plug and socket make contact, the charging connection is established and the energy storage unit is rechargeable. The information exchanged between the charging station and the vehicle, once the charging connection has been established, includes information about the electrical status of the energy storage unit, so that the decoupling motion can be initialized once the charging connection has been established and/or once the energy storage unit is fully recharged. When the decoupling motion is carried out, the plug-socket connection is disconnected.
This embodiment offers the advantage that the vehicle can be automatically disconnected from the external charging source regardless of the status of the recharging process or it is disconnected automatically once the energy storage unit is full. The user of the vehicle does not have to operate the charging device manually.
In addition, each insertion funnel has a cover, which can be opened to establish a charging connection and which can be closed, if the charging connection is not established. This ensures that the socket is secure particularly while driving.
The invention is based on the following considerations. For electric vehicles, the conductive, i.e. cable-based, charging process with a manually pluggable charging connection has been established as the state of the art. At the same time, many manufacturers are researching automatic inductive procedures. Automatic and partially automatic procedures for conductive systems are known from other technical fields. In this context, docking stations for laptops or charging devices for electric lawnmowers, are known.
However, plugging in a charging cable manually to a vehicle can be rather uncomfortable. For example, the user can get dirty from the cable. Inductive procedures require complex technology and therefore they are rather expensive and require a larger installation space and have an increased weight. Moreover, the inductive charging technology through magnetic fields is associated with high transfer losses. Automatic coupling systems from alternative applications such as railway technology and automation technology do not satisfy the demanding and safety-relevant requirements for use in automotive applications. For example, this concerns high-voltage safety and the robustness in view of numerous environmental influences. Specific requirements are created due to the necessity of excluding any risks to persons that may be caused by mishandling by untrained persons during operation.
As an improved measure, a device and procedure to connect the vehicle automatically to a charging device are provided. For this purpose, the vehicle is initially roughly positioned, whereby the rough positioning is given by the position of the underside of the vehicle compared to the components of the charging device. The bendable charging cable is moved toward the charging socket of the vehicle through linear motion. The end of the charging cable that points toward the vehicle has a charging plug and a defined flexural rigidity, for which reason it is also called an insertion rod. The charging socket of the vehicle has an insertion funnel. Alternatively, the insertion funnel and the charging plug are flexible or the charging cable is flexible after the insertion rod, so that the precise position of the charging plug at the target location, i.e. the charging socket, is enabled. The three spatial directions are covered through the linear motion and through the flexible position or flexibility of the cable. In addition, the plug and the socket are designed to be rotationally symmetrical, so that it even covers the degree of rotation freedom of the plug with regard to the socket. These procedures can be modified through numerous embodiments.
The advantage of the measure is that conventional components can be used. In particular with regard to the vehicle, this solution is not extensive and is of low weight, requires little space and is inexpensive. The electrical connection is based on the interface specified in the standards. If it is installed on the ground, it is beneficial that it offers protection from vandalism and weather in a connected condition.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
Same reference numbers are used the drawings to describe identical characteristics or parts.